Ticagrelor, (1S,2S,3R,5S)-3-[7-[[(1R,2S)-2-(3,4-difluorophenyl)cyclopropyl]-amino]-5-(propylthio)-3H-1,2,3-triazolo[4,5,d]pyrimidine-3-yl]-5-(2-hydroxyethoxy)-1,2-cyclopentanediol, has the following chemical structure:

Ticagrelor is currently marketed in Europe under the trade name BRILIQUE™ BRILIQUE™ is purportedly a reversibly binding oral P2Y12 ADP receptor antagonist.
Ticagrelor can be obtained by a process as shown in the following scheme, as described in PCT Publication No. WO00034283:

Although the process shown above produces the desired Ticagrelor product, several of the process steps incur significant problems that adversely affect the cost, yield, safety and environmental impact of the process as a whole. For example, in the process above, intermediates (9), (10), (12), (13), (15) and (16) are isolated as oils/liquids, making these intermediates much more difficult to handle and purify on a commercially useful scale. In some steps in the above process the conversion is low. For example, the coupling of intermediates (6) and (7) to prepare intermediate 8, results in a product that contains about 25-30% of a dimer byproduct that results from reaction of both chloro groups on intermediate (7). Another process step which does not proceed to completion is the reaction to form intermediate (12). This step has only about 40% conversion and produces a problematic triol byproduct, which can't be removed by crystallization because intermediate (12) is not a solid. Another potential problem with this step is that the methyl 2-(trifluoromethylsulfonyloxy)acetate reagent used therein is not commercially available and must be prepared using a reagent such as triflic anhydride, which is both expensive and hazardous. In addition, the final step of deprotection of the diol to produce Ticagrelor results in substantial racemization of the cyclopropyl amine.
There is a need in the art for improved processes for synthesizing Ticagrelor which are suitable for industrial use.